1. Field of the Invention
This invention relates generally to a container, and more particularly to a container that provides a controlled hydrated environment for the shipping and storage of microfluidic devices.
2. Background of the Invention
The use of microfluidic technology has been proposed for use in a number of analytical chemical and biochemical operations. This technology provides advantages of being able to perform chemical and biochemical reactions, macromolecular separations, and the like, that range from the simple to the relatively complex, in easily automatable, high-throughput, low-volume systems. The term, “microfluidic”, refers to a system or device having channels and chambers, which are generally fabricated at the micron or submicron scale. In particular, these systems employ networks of integrated microscale channels in which materials are transported, mixed, separated and detected. The working part of the device or chip is made of quartz, fused silica, or glass. The working part is then bonded with a UV-cured adhesive to a plastic mount, such as an acrylic or thermoplastic mount.
One variety of microfluidic devices is called a “sipper” chip. In sipper chips, at least one small glass tube or capillary (the “sipper”) is bonded perpendicularly to the substrate of the chip. Typical sipper chips use one to twelve sippers. Once the user prepares the chip and places the chip into a reading instrument, minute quantities of a sample material can be introduced, or “sipped” through the capillary to the chip. This sipping process can be repeated many times enabling a single chip to analyze thousands of samples quickly and without human intervention.
The sipper must be wet prior to use in order to enable the start of flow of sample material into the chip. Because the sipper has a perpendicular orientation with respect to the chip, air bubbles can form easily within the sipper. Such air bubbles can prevent the capillary action of the sipper from drawing the sample material into the channels of the chip. Wetting the sippers correctly (i.e., without forming air bubbles) can be difficult and requires training and skill. Therefore, the sippers are pre-wetted during the final stages of manufacture, so that the formation of air bubbles can be prevented. The sippers must remain wet until use, so the chips are shipped and stored in a hydrated environment.
Additionally, sipper chips are typically shipped after having been preconditioned with sodium hydroxide under pressure. The preconditioning process prepares the surface of the chip for use and increases the lifetime of the chip. The extremely caustic nature of the preconditioning fluid makes it desirable to have the preconditioning performed by technicians prior to shipping as opposed to having the end user apply the sodium hydroxide. The chips are then shipped wet to preserve the preconditioned surface state.
Current shipping and storage methods of wet microfluidic chips typically entail the use of a fluid-filled container. The fluid is generally distilled water containing a preservative such as EDTA or a buffer such as Tris-Tricene. The chip is then submerged in the fluid and suspended in the submerged position. This type of shipping container is undesirable for various reasons. First, the end user must “fish” the chip out of the fluid in which it has been shipped. Secondly, the submersion may weaken the adhesive bonding of the working part of the chip with the plastic mount, resulting in delamination and an unusable chip. Finally, as the chips are capable of being reused many times, the user must replace the chips into the storage fluid between uses, which increases the risk of contaminating the chip.